Remote control system



E. M. ALLEN REMOTE CONTROL SYSTEM Oct. 10, 1939.

Filed Aug. 25, 1938 2 Sheets-Sheet 1 QQN L f W kg .QNQ aw Esi Eww @EP W 0 m m mm m Qk Oct. 10, 1939. E ALLEN 2,175,586

REMOTE CONTROL SYSTEM Filed Aug. 25, 1938 2 Sheets-Sheet 2 g b RT Y mm T Y ww w 5% hvwmwl \wbvw DW 1 b \N Raw N NM mm Raw .mN \NQNN b QM RN 4 \WFNN KUAWN .U

INVENTOR Earl lien HIS ATTORNEY \NN \NNNMN .k E In "NU n j kw Sm M v EQNR vRW 3 m \E QQE Patented Oct. 10, 1939 UNITED STATES PATENT OFFKQE REMOTE CONTROL SYSTEM Application August 25, 1938, Serial No. 226,756

Claims.

My invention relates to remote control systems, and more particularly to remote control systems for railways.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

A feature of my invention is the provision in remote control systems of the type here contemplated of novel and improved means for controlling a plurality of different devices from a remote point and for indicating at the control point the respective positions of such devices. Another feature of my invention is the provision in a system of this character of apparatus to both control a device from a remote point and to continuously indicate at such point the position of the device by virtue of a single two-wire line circuit, one wire of which may serve as a common wire for several such line circuits. Again, a feature of the invention is the provision in a system of this character when it employs sources of current of reversible polarity at both ends of a two-wire line circuit of novel and improved circuit switching apparatus for connecting only one source to the line circuit at a time. When apparatus embodying my invention is applied to the control of railway track switches and signals, an additional feature of the invention is the provision of apparatus for remotely controlling and indicating such track switches and signals wherewith additional line wires, when the number of switches and signals is not balanced, are avoided. Other features and advantages of my invention will appear as the specification progresses.

In the accompanying drawings. Figs. 1a and 1b, when taken together with Fig. 1b placed at the right of Fig. 1a., are a diagrammatic view of one form of apparatus embodying my invention when applied to the control and indication of railway track switches and signals. It will be understood, of course, that I do not wish to limit my invention to the control of railway track switches and signals, but this one use of apparatus embodying my invention will serve to illustrate the many places where the invention will be useful.

Referring to the drawings, the lineargraph at the upper right-hand portion of Fig. 1b designates a stretch of double track railway provided with a crossover CV to permit traflic to move between 50 an eastbound track EB and a westbound track WB. The eastbound track EB is formed in the usual manner with a detector track section 2T which extends to the limits of the crossover, and in like fashion the westbound track WB is formed with a detector track section 4T, Each of these track sections is provided with a track circuit which includes a track relay designated by the reference character R plus a prefix corresponding to the reference character of the section, the relationship of each track relay with its section 5 being indicated by a dash line.

In accordance with standard practice, signals R2 and L2 are located at the opposite ends of the track section 2T for governing traffic through the section, the signal R2 being provided with signal 10 mechanisms RZA, RZB and R20 mounted on a single mast, and the signal L2 being provided with but one mechanism. Signals L4 and R4 are provided at the opposite ends of track section 4T for governing trafiic through that section, the signal 15 L4 comprising three signal mechanisms L4A, L4B and L4G mounted on a single mast, and the signal R4 having but one mechanism.

It should be pointed out that signals R2 and L2 form what is commonly referred to as a right signal and a left signal for governing traffic in opposite directions over a track section having a track switch, and which signals are selectively governed by a single controlling unit. The signal mechanisms RZA and L2 are used when the crossover CV is at its normal position, signal mechanism R218 is used when the crossover is at its reverse position for directing traffic from track EB to track WB, and the signal mechanism R26 is used as a so-called call-on signal. 30 Again, signals L4 and R4 form right and left signals for governing tramc over the track section 4T, which track section is also associated with the track switches of the cross-over CV, signal mechanisms L4A and R4 being used when the 35 crossover is set at the normal position, signal L4B being used when the crossover is set at its reverse position, and signal mechanism L lC being a call-0n signal.

In other words, this track layout requires an 40 unbalanced condition between the switch control and the signal control since the track switches of the crossover require but one normal and reverse control, while the associated signals require three such controls, one signal control for 4.5 the right signals RZA and RZB and the associated left signal L2, a second signal control for the right signal R4 and the left signals MA and LAB, and a third signal control for the call-on signals L lC and R20. This unbalanced condition of the related devices (switches and signals) will be re ferred to later on in the description.

Additional signals would, of course, be provided for governing traffic approaching the signals at the crossover, but such additional signals are 55 not shown since they are not required for a full understanding of my invention.

The signal mechanisms may be of any wellknown form, and are shown conventionally for the sake of simplicity.

The two track switches for the cross-over CV are preferably operated by power switch machines SMI and SM2. The type of switch machine is immaterial, and they are shown by the symbol commonly used to indicate such power switch machines. It is sufficient for the instant application to point out that each switch machine SMI and SM2 would preferably include a reversible electric motor (not shown) which, when supplied with current of one polarity, is operated to move the associated track switch to one of its extreme positions, and when supplied with current of the opposite polarity is operated to move the switch to its other extreme position, the operation of the two motors for switch machines SMI and SM2 being made dependent upon each other so that the two ends of the crossover always agree as to position.

Control of the switch machines SMI and SM2 of the crossover CV and of the associated signals is effected in part from a remote control point CO (Fig. 1a) such as, for example, a dispatchers ofiice, through the medium of apparatus located partly at the office station CO and partly at a field station FL, which latter station is preferably located adjacent the crossover. Each station CO and FL is provided with a suitable source of current which in this instance is a battery, a battery [2 being located at station CO and a battery [3 being located at station FL. In order that current of normal and of reverse polarity may be supplied, the batteries l2 and I3 are preferably provided each with a positive terminal Bl, a negative terminal NI and a mid or center terminal C.

Referring first to the apparatus located at the field station FL, a polarized relay WR is provided for governing the switch machines SMI and SM2, the arrangement being such that when the relay WR. is energized by current of normal polarity and its front neutral contact 4 and normal polar contact 5 are closed, current is supplied from terminal Bl of the current source over wire 6 to the motor of the switch machine SMI to move the associated track switch to its normal position, and the circuit is extended over wire 1 to the motor of the switch machine SM2 to move the associated track switch to its normal position. In each case the circuit for the motor is completed to the terminal NI of the current source over wire 8. When the relay WR is energized with current of reverse polarity and its front neutral contact 4 and reverse polar contact 9 are closed, current is supplied over wire In to the motor of the switch machine SMI for moving the associated track switch to its reverse position, and the circuit is extended over wire H to the motor of the switch machine SM2 for operating the associated track switch to its reverse position. The switch controlling relay WR is preferably slow releasing in character, and the control thereof will be described hereinafter.

Before proceeding further with the description, it should be pointed out that contact fingers of the track relays 2TB. and 4TB and of the polarized relay WR, as well as of other relays to be later referred to, are for the sake of clearness shown remote from the windings of the relays. In each case the contact finger is identified by the reference character of the relay and is illustrated in the position corresponding to the nor mal energized or deenergized condition of the relay winding. In other instances contact members are shown remote from their operating device, and these contact members are in each case identified by the reference character of the operating device, and each is illustrated in the position corresponding to the normal position of the operating device.

A switch indication relay KR and a repeater relay WKRP are associated with the switch controlling relay WR. The relay KR is a polarized relay energized by current of normal polarity when the track switches of the crossover both occupy their normal positions so that the contact members 34 and 35 operated by machine SMI and its associated track switch, and the contact members 36 and 3'! operated by the switch machine SM2 and its associated track switch occupy the positions illustrated by the solid lines in the drawings, and the normal polar contact 38 of relay WR is closed. Relay KR is energized by current of reverse polarity when the crossover CV is set at its reverse position so that the respective contact members 34, 35, 36 and 37 occupy the positions illustrated by the dotted lines and the reverse polar contact 39 of relay WR is closed. The relay WKRP is energized over a simple circuit including back contact 40 of relay WR in multiple with a back contact 4| of relay KR, a resistance HH being preferably connected across the winding of relay WKRP to provide the relay with slow release characteristics.

The apparatus at the field station FL is provided with a signal control relay for each of the several signals, such signal control relays being identified by the reference character H plus a prefix corresponding to the reference character of the signal it governs. For reasons to appear hereinafter, the signal control relays for signals L IA, LtB and R4 are omitted from the drawings. The operating circuits for each signal are controlled by the associated signal control relay according to standard practice, and these operating circuits are not shown in order to not unduly complicate the drawings since such operating circuits are well known and they form no part of my present invention. It is deemed sufficient to say that when a signal control relay is deenergized, the associated signal assumes a stop position, and the signal is operated to a proceed position when the signal control relay is energized. For example, the signal control relay RZAH, when deenergized, causes signal RZA to assume its stop position, and, when energized and picked up, it causes the signal RZA to assume a proceed position.

The signal control relays R2AH, RZBH and L2H are controlled by a polarized relay ZHR, since, as pointed out hereinbefore, these signals comprise what is commonly called right and left signals for governing traffic over the track section 2T, and are selectively controlled by a normal and a reverse control. With relay ZHR energized by current of normal polarity so that its front neutral contact 14 and normal polar contact I5 are closed, the relays R2AI-I and RZBH are selectively energized according to the position of the crossover CV and in response to traffic conditions in advance of the signal. The circuit for relay RZAH involves battery terminal Bl, front contact I4, normal polar contact 15, winding of relay RZAI-I, a traffic controlled circuit network I6, contacts I! and I8 operated by the track switches of the crossover CV and closed when each switch of the crossover occupies its normal position, and battery terminal C. With the crossover moved to its reverse position so that the contact members I! and I8 occupy the positions illustrated by the dotted lines in the drawings, the relay RZBH is selected, it being assumed, of course, that the trafic controlled circuit network I9 is also closed. Relay ZHR, when energized by current of reverse polarity so as to close its front neutral contact I4 and reverse polar contact 20, governs a circuit for signal control relay L2H, the circuit being completed over contact members 2| and 22 closed with the track switches of the crossover CV in their respective normal positions, and over a traffic controlled circuit network 23. It should be noted that contacts I! and I8 as well as contacts 2| and 22 may be polar contacts operated by the switch indication relay KR. In other words, the polarized relay Zl-IR, when energized at normal polarity, selectively controls signals RZA and B2B according to the position of the crossover for governing eastbound trafiic operating over track section 2T, and, when energized by current of reverse polarity, it controls signal L2 for governing westbound traflic operating over track section 2T.

Since the signals L lA, LIB and R4, as pointed out hereinbefore, constitute right and left signals that govern traffic over the track section 4T, which is also associated with the crossover CV, the field station apparatus would include another signal controlling polarized relay similar to the relay 2HR for governing the signal control relays for the signals L4A, LAB and R4, and which polarized relay when energized at normal polarity would selectively control signals L4A and LAB according to the position of the crossover, and when energized with current of reverse polarity would govern the signal R4. This polarized relay and the signal control relays for signals L SA, LGB and R4 are not shown, however, since the control thereof is but a duplication of the control of relay 2BR and its associated signal control relays, and it is thought such duplication of apparatus would only complicatethe drawings without adding to the understanding of the invention.

The call-on signals R20 and L4G, which also require a normal and a reverse signal control, are governed through the medium of a polarized relay 2-4CO provided in the apparatus at the field station FL. When the polarized relay 2-4CO is energized at normal polarity, causing its front neutral contact 24 and normal polar contact 25 to be closed, a simple pick-up circuit is formed for the signal control relay RZCH. The signal control relay RZCH is provided with a stick circuit including front contact 26 of the signal control relay RZAI-I and a front contact 21 of the relay RZCH. Hence, the signal control relay RZCH is operated to clear the call-on signal RZC only if the signal control relay RZAH for signal R2A has first been picked up, the call-on signal R2C being used in the usual manner when the signal R2A has for some reason failed to operate. The polarized relay 2-.4CO, when energized at reverse polarity to close front neutral contact 24 and reverse polar contact 28, completes a circuit for signal control relay L4CH for the signal LC4, the relay L4CH being also provided with a stick circuit including front contact 29 of signal control relay L4AH (not shown) and its own front contact 30, so that the call-on signal L40 would be used only if the signal L4A for some reason failed to operate.

It is again pointed out that the track layout shown in Fig. 1b requires an unbalanced condition between the switch control and the signal control because the track switches of the crossover CV require but a single normal and reverse control for governing the polarized relay WR, whereas the associated signals require three such normal and reverse controls, one for governing the polarized relay 2HR which controls signals RZA, RZB and L2; a second such control for governing a polarized relay to control the signals L4A, LAB and R4; and a third such control for governing the polarized relay 2--4CO which controls the call-on signal R2C and L4C.

The winding of each of the polarized relays WR, ZHR and 2-4CO is interposed in a two-wire line circuit extending between the oflice station CO and the field station FL, the line circuit for relay WR including a control line wire WI and a common line wire CL, the circuit for relay 2I-IR including a control line wire W2 and common line Wire CL, and the circuit for relay 24CO including a control line wire W3 and common line wire CL.

At the field station FL the first mentioned line circuit involves, when the crossover CV is set at its normal position, line wire WI, approach looking circuit contacts 65, 66, 61 and 68, front contacts G9 and 79 of track relays 2TB, and 4TB, respectively, winding of relay WR, back contact ll of relay WKRP, normal polar contact 12 of relay KR, and terminal Nl of battery I3, the common line wire CL being connected to the center terminal C of battery 13. In the event the crossover CV is set at its reverse position so that the relay KR is energized at reverse polarity, the above traced line circuit is completed at reverse polar contact 73 of relay KR and the positive battery terminal Bl. Consequently, current of normal or reverse polarity is supplied from bat tery G3 to this line circuit through the winding of relay WR according to the position of the crossover except when a movement of the crossover is to be effected. As will be later pointed out, the current thus supplied to the line wire WI from battery l3 serves to indicate the position of the cross-over CV as well as to energize the polarized relay WR. The approach locking circults in which the contacts 65 to 68 are controlled would be in accordance with standard practice and are not shown for the sake of simplicity. When conditions are such as to cause the usual manner the release of one of the approach locking circuit contacts 65 to 68, or when either detector track section 2T or 4T is occupied to cause the release of track relay 2TR, or 81%,, the line wire WI is disconnected from relay WR and the relay WR is retained energized by virtue of a local circuit which is completed at one of the back contacts 74 to 19, inelusive, as will be readily understood from an inspection of Fig. lb. Again, at such time as the relay WKRP is picked up, closing front contact 8!], a connection is completed for this line circuit around the battery l3, the right-hand terminal of the winding of relay WR being now connected directly with the common line wire CL.

The polarized relay 2HR is interposed in the second mentioned line circuit by virtue of the line wire W2 being connected to the left-hand 1 ferred to later. At such time as the relay L2]? is released, closing back contact I93, this line circuit is connected to the positive terminal BI of battery I3, and when relay L2P is picked up, closing front contact BI, and relay R2]? is released, closing back contact I04, this line circuit is connected to the negative terminal NI of battery I3.

The polarized relay 24CO is interposed in the last mentioned line circuit, the left-hand terminal of the winding of relay 24CO being connected with the line wire W3, and the right-hand terminal of the winding of the relay being connected with the common line wire CL. These fine circuits will be again taken up after the apparatus at the ofiice station is described.

The apparatus of the field station FL also includes two signal repeater relays R2P and L2P for checking the positions of the signals RZA, RZB and L2. The circuit for relay R2P includes back contacts 3|, 32 and I32 of the signal control relays RZAH, REBH and R2CH, respectively. When all three relays RZAH, R2BH and RZCH are deenergized so that the respective signals are at their stop positions, the relay R2P is energized, but when either relay R2AH, RZBH or RZCH is picked up to operate the respective signal to a proceed position, the relay RZP is re leased. The relay LZP is controlled over back contact 33 of the signal control relays L2H, and is hence energized when relay L2H is deenergized so that signal L2 is at its stop position, and relay L2P is deenergized when relay L2H is picked up to operate the signal L2 to a proceed position. These signal repeater relays RZP and L2P are provided with slow release characteristics and are, for reasons to later appear, each so constructed that, when the relay is released, an interval between the opening of the front contact of the relay and the closing of its back contacts is assured. That is, there is an interval between the opening of front contact 8| of relay L2P and the closing of its back contact I03; and there is a like interval between the opening of front contact 82 of relay RZP and the closing of its back contact I04. It is also to be pointed out that relay WKRP is adjusted so that a similar interval exits between the opening of the front contact and the closing of its back contact lI.

Referring to the office station apparatus, a switch lever IL, two signal levers 2L and 4L and two push buttons ZPB and iPB are mounted for convenient manual operation. As will shortly appear, switch lever IL is used togovern control current applied from the Office station battery I2 to the line circuit including line wire WI for energizing the polarized relay WR to govern the switch machines SMI and SM2. The signal lever 2L is used to govern control current applied from the battery I2 to the line circuit including line wire W2 to energize the polarized relay 2H5, for controlling the associated signal control relays of the the signals R2A, B2B and L2. The signal lever 4L is used in a manner similar to the signal lever 2L for governing the signals L4A, L4B and R4. The push buttons ZPB and 4PB are used to control current supplied to the line circuit including line wire W3 to energize the polarized relay 2-4CO for governing the signals R20 and L4C.

The switch lever IL comprises a manually operable handle 42 and circuit controlling contact members 43 to 49, inclusive. The handle 42 is capable of moving the lever to a normal position N and to a reverse position R, and the several contact members are connected with the handle for closing contacts at different positions of the lever. The signal lever 2L comprises a manually operable handle 58 and circuit controlling contact members 5I to 56, inclusive. The handle 50 is capable of moving the lever from a mid or normal position N to either a right position RT or to a left position LT, and the several contact members are connected with the handle 50 for closing contacts at different positions of the lever. The signal lever 4L is provided with three positions, N, LT and RT, the same as the signal lever 2L, and the lever 4L will be again referred to later on. The push buttons ZPB and 4PB are of the spring return type, push button 2PB closing a contact 51 when depressed and the push button 4PB closing a contact 58 when depressed.

In order to at times connect the battery I2 with the line circuit including line wires WI and CL to energize the polarized relay WR in accordance with the position of the switch lever IL and at other times to connect this line circuit around the battery i2 for receiving at the office station indication current supplied to the line circuit at the field station according to the position of the crossover CV, the office station apparatus includes a circuit switching means which comprises relays WRP, WKP, LPS and LVP. The relays WKP, LPS and WRP are neutral relays, with relay WKP being provided with a selected slow release period, relay LPS being quick to pick up and slow to release, relay WRP being of the ordinary acting type. Relay LVP is a polar relay characterized by its polar contacts remaining closed in their last position when the relay is deenergized.

Normally the winding of the relay WKP is interposed in a connection between the line wires WI and CL around the battery I2. This connection can be traced from line wire WI over back contact 83 of relay LPS, back contact 84 of relay WRP, winding of relay WKP, and wire 85 to terminal C of battery I2, to which terminal the line wire CL is also connected. Since, as pointed out hereinbefore, the battery I3 at the field station is normally connected with this line circuit, it follows that the relay WKP at the ofiice station is normally energized in series with the polarized relay WR at the field station. At such time as relay LPS is picked up, closing front contact 86, and relay WKP is released, closing back contact 81, the relay WRP is interposed in a connection for supplying current from battery I2 to this line circuit. When the polar relay LVP is set at its normal position in a manner to shortly appear, a connection extends from terminal BI of battery I2 over normal polar contact 88 of relay LVP, winding of relay VVRP, back contact 81 of relay WKP, front contact 86 of relay LPS and line wire WI. When the polar relay LVP is set to close its reverse polar contact 89, this connection is completed from the negative terminal NI of battery I2.

Selection between the connection including relay WKP and the connection including relay WRP and the battery I2 is cifected through the medium of relay LPS, the back contact 83 of relay LPS being interposed in the first mentioned connection and front contact 86 of relay LPS being interposed in the second mentioned connection. Relay LPS in turn is provided with a pickup circuit which is closed during a movement of the switch lever IL between its two positions N and R, and which circuit extends from terminal BI of battery I2 over front contact 90 of relay WKP, contact 4l-9I closed between the N and R positions of the lever IL but open at both extreme positions of the lever, winding of relay LPS and terminal C. The relay LPS is also provided with a stick circuit, one branch path of which includes front contact 92 of relay WKP, resistance 93 and its own front contact 94, and a second branch path of which includes the terminal Bl, back contact 95 of relay WRP, contact member 48 when lever IL is at its normal position or contact member 49 when lever IL is at its reverse position, back contact 96 of relay WKP, and then as before traced.

The polar relay LVP is selectively energized according to the position of the switch lever IL, the arrangement being such that with relay LPS picked up, closing front contact 97, and lever lL set at its normal position N to move contact member 45 to a corresponding position the lower winding 98 of relay LVP is supplied with current over a simple circuit easily traced, and the relay is energized at normal polarity to close its normal polar contacts 52 and 88, but when the lever IL is moved to its reverse position R to move contact member 46 to a corresponding position the upper winding 99 of relay LVP is supplied with current and the relay is energized at reverse polarity to close its reverse polar contacts 53 and 89.

A normal indication lamp NL and a reverse indication lamp RL are disposed adjacent the switch lever IL. An inoperable or approach lock indication lamp OS is also mounted at the lever IL to indicate when, due to traffic conditions, the crossover cannot be controlled by the switch lever IL. The immediate control of the lamps NL, RL and OS is effected by contact members 43 and. 44 of the lever and the relays associated with the line circuit comprising wires WI and CL. With the lever IL at its normal position N, the lamp NL is illuminated by virtue of a circuit including terminal BI, back contacts 59 and 60 of the respective relays LPS and WRP, front contact GI of relay WKP, normal polar contact 62 of relay LVP, contact member 43, lamp NL and battery terminal C. In the event the lever IL is moved to its reverse position R, the lamp BL is illuminated over the same circuit up i to front contact 5! and thence over reverse polar contact 63 of relay LVP, contact member 44. lamp RL and terminal C. When relay WKP is released in a manner to later appear, the lamp OS is illuminated over a circuit including back contacts 59, 60 and 64.

The office station apparatus is also provided with a circuit switching means governed by the signal lever 2L for at times connecting the battery I2 with the line circuit comprising line wires W2 and CL and to at other times provide'this line circuit with a connection around the battery I2 for receiving at the office station an indication current supplied to the circuit at the field station. This circuit switching means comprises relays HRP, HKPS and HRPP, the relay HRPP being provided with a selected slow release period, relay HRP being quick to release and relay HKPS being of the ordinary acting type. With lever 2L moved to its RT position, a connection is completed from terminal BI of battery I2 over contact member 55 of lever 2L, winding of relay HRP, back contacts I05 and I06 of relays HRPP and HKPS, respectively, and to the line wire W2, and current flows from terminal BI of battery I2 over the line wire W2 to the field station, through the winding of relay ZHR at the field station, and back to the ofiice station over line wire CL, with the results that the relay HRP is energized in series with the polarized relay ZHR. Relay HRP, on picking up, closing front contact Ili'I, completes a shunt path for this line circuit connection around the back contacts 505 and 16. When lever 2L is moved to its LT position, the terminal NI of battery I2 is connected to the line circuit over the same connection, and relay HRP is energized and picked up in series with the polarized relay ZHR at the field station. For signal indication, the connection for line circuit including line wires W2 and CL around the battery I2 can be traced from wire W2 over back contact I of relay HRP, front contact IliI of relay HRPP, winding of relay HKPS, contact member 53 of lever 2L at its LT position or contact member 54 with lever 2L at its RT position, and wire I02. When relay I-IKPS is picked up, closing front contact I08, this last traced connection is completed around the front contact it i The relay HRPP, the back contact E85 of which is interposed in the first connection associated with the line wire W2 and the front contact Ifii of which relay is interposed in the second connection for this line circuit, serves to select between the two connections. Relay HRPP also serves to provide the so-called stick control for the signals governed by the lever 2L as will shortly appear. The relay HRPP is controlled over a pick-up circuit including front contact I 99 of the relay HRP, and is provided with a stick circuit which includes the contact member 56 of the lever 2L, an emergency contact III and its own front contact IIU.

Three signal indication lamps I 52, H3 and H4 are mounted adjacent the lever 2L and are illuminated to indicate the position of the signals governed by this lever in a manner to be pointed out when the operation of the apparatus is described. The immediate control of lamp H2 includes back contact II of relay LIKPS. Lamp H3 is illuminated when the lever 2L is moved to its LT position, and the front contact H6 of relay I-IKPS is closed. Lamp H4 is illuminated when the lever 2L is moved to its RT position and the front contact IIG of relay HKPS is closed.

Referring to the third line circuit comprising line wires W3 and CL, a connection is provided from positive battery terminal BI when push button ZPB is depressed to close contact 5?, and a connection is completed from negative terminal NI of battery I2 when the push button PB is depressed, closing contact 58.

In describing the operation of the apparatus, I shall assume at the start that the crossover CV is normal, the associated signals are all at stop position, and the control levers at the ofiice station are at their respective normal positions. Under this normal condition current of what I shall call normal polarity for indication is supplied from battery I3 at the field station to the line circuit including line wires WE and CL so that the relay WKP is picked up and the relay WR is energized at normal polarity. It is to be noted that this current flows from terminal C of battery I3 over line wire CL to terminal C at station CO, wire 85, winding of relay WKP, back contacts 84 and 83, line wire WI, front contacts 65 to ID, inclusive, winding of relay WR, back contact II, normal polar contact I2 and terminal Ni of battery I3. With relay WR, thus energized, any creeping or false movement of the crossover CV away from its normal position will cause current to be again supplied to the switch machines SMI and SM2 to restore the track switches. With relay WKP picked up, closing front contact 6|, the normal lamp NL is illuminated to indicate the normal position of the crossover.

With the signal lever 2L at its normal position, the line circuit comprising the line wires W2 and CL is open, with the result that the polarized relay ZI-IR. is normally deenergized to cause the signals controlled by this relay to be at the stop position. Also, the relay HKPS at the office station is deenergized, closing back contact H5, causing the lamp III! to be illuminated to indicate at lever 2L the stop position of the associated signals. If the operator wishes to operate the signal R2A to permit a train on track EB to move east (right) over the track section 2T, with the cross-over at its normal position, the signal lever 2L is moved to its RT position. Contact member of relay 2L now completes a connection from positive terminal BI of battery I2 to the line wire W2, and current which I shall call positive or normal polarity, is supplied to this line circuit 50 that the relay HRP is picked up and the polarized relay 2HR is energized at normal polarity. The picking up of relay HRP closes front contact i09, energizing the relay HRPP, and that relay on picking up opens at back contact I05 the connection to the line circuit, but this connection is maintained by virtue of a path around back contact I05 which is closed at front contact I01 of relay I-IRP.

At the field station the energizing of relay 2HR at normal polarity selects the signal control relay RZAH and the signal R2A is operated to a proceed position. When signal control relay RZAI-I picks up. opening back contact 3I, the signal repeater relay RZP is deenergized and releases at the end of its slow release period. During the interval between the opening of front contact 82 of relay R2? and the closing of its back contact I04, the line circuit is open and relay HRP at the oflice station is released to open at its front contact I01 the connection to battery I2 and to close at its back contact I00 the connection for this line circuit around the battery I2, it being recalled that relay HRP is quick acting. When the back contact I04 of relay R2P is closed, indication current flows from terminal C of battery I3 over line wire CL, wire I02, contact member 54, Winding of relay HKPS, front contact IOI of relay HRPP, back contact I00 of relay I-IRP, line wire W2, winding of relay 2HR, front contact BI of relay L2P, back contact I04 of relay RZP and to the negative terminal NI of battery I3. Relay HKPS is now picked up and relay ZHR is still energized at normal polarity since the indication current supplied to the line circuit from battery I3 flows through the winding of relay ZHR. in the same direction as the control current supplied from battery I2 at the oflice station. With relay ZHR. still retained energized at normal polarity, the signal control relay RZAH is retained energized to operate the signal RZA. The picking up of relay HKPS to open back contact I I5 and to close front contact IIB causes the lamp II2 to be extinguished and the lamp H4 to be illuminated to indicate the proceed position of signal RZA. This indication circuit for signal RZA is retained until such time as the train advances beyond the signal R2A and opens the circuit for relay RZAH at the traffic controlled contact I6. With relay R2AH released to restore signal R2A to its stop position, the closing of back contact 3| completes the circuit for relay RZP, and that relay is reenergized and picked up with the result that the associated line circuit is restored to its normal open position and relays HKPS and 2HR are deenergized. The releasing of relay HKPS causes lamp Ill to be extinguished and the lamp II2 to be illuminated to indicate the stop position of the signal. Since the relay HRPP is retained energized over its stick circuit, the associated line circuit is held open at back contact I05 of relay HRPP until such time as the lever 2L is restored to its normal position, and the stick circuit for relay HRPP is opened at contact member 56. It follows that signal R2A will not be again operated to a proceed position when the traffic controlled contact I6 is reclosed until the operator first returns the lever 2L to its normal position and then again moves the lever to its RT position. That is, the so-called stick control for the signal is effected by virtue of the stick circuit for relay HRPP. To remove such stick control for the signal, the contact III would be set at its open position so that the relay HRPP is controlled by its pick-up circuit only.

In the event the signal L2 is to be operated to permit a train to move to the track section 2T in a west-bound direction, the signal lever 2L is moved to its LT position where contact member 55 completes the connection for the line circuit including line wire W2 to the terminal NI of battery I 2, and the relay HRP is picked up and the polarized relay ZHR at the field station is energized at reverse polarity. The signal control relay L2H is now picked up to operate the signal and the repeater relay HRPP at the office station is energized. With relay L2H picked up to operate the signal L2, the signal repeater relay L2? is deenergized and releases at the end of its slow release period. During the interval between the opening of front contact 8| of relay L2P and the closing of its back contact I03, the line circuit is open and the relay HRP is released to disconnect the battery I2 from the line circuit and to complete the connection around battery I2 and which connection includes the relay HKPS. Current now flows from terminal BI of battery I3 at the field station to the line circuit and the relays 2I-IR. and HKPS are energized. Relay 2I-IR is still energized at reverse polarity since the indication current supplied from battery I3 flows in the winding of the relay in the same direction as the control current supplied by battery I2 at the office station with the lever 2L at its LT position. When relay HKPS is picked up, the lamp H2 is extinguished and the lamp H3 is illuminated to indicate the proceed position of signal L2. When this train advances to the left of signal L2 and operates the traflic controlled contact 23, the signal relay L2H is deenergized and the signal L2 is restored to its stop position. The signal repeater relay L2P is now picked up so that the associated line circuit is open and the two relays HICPS and 2HR. are restored to their normal deenergized condition. The indication lamp II 3 is now extinguished and the lamp 2 is illuminated to again indicate the stop position of the signal.

In the event the signal RZA should fail to respond to the picking up of the signal control relay R2AH in the manner previously described, the operator in order to operate the call-on signal R20 would depress the push button ZPB for an interval to close the connection from terminal BI of battery I2 to the line wire W3 for energizing the polarized relay 24CO at normal polarity. The signal control relay RZCH is selected and is then retained energized over its stick circuit including the front contact 26 of the signal control relay R2AH with the result that the call-on signal REC is operated.

As mentioned hereinbefore, the apparatus associated with the signal lever 4L for controlling a polarized relay to operate the second mentioned set of right and left signals (signals L4A, L4B and R4) is omitted from the drawings since such apparatus and associated line circuits would be but a duplication of the apparatus and line circuits associated with the signal lever 2L, and it is thought such duplication would not add to the understanding of the invention.

Starting again with the apparatus at its normal condition and assuming that the operator desires to reverse the crossover CV, the switch lever IL is moved to its reverse position R. During the movement of the lever IL between position N and position R, the contact member 41 engages contact 9! to complete the pick-up cir cuit for relay LPS, and this relay is picked up and is then retained energized by virtue of its stick circuit subsequent to the lever IL set at the full reverse position R. With relay LPS picked up, the line circuit including line wire W i is open so that both relays WKP and WE are deenergized and both are released at the end of their respective slow release periods. The slow release period of relay WKP is selected to be somewhat longer than the release period WR so that back contact 40 of relay WR is closed and relay WKRP is picked up prior to the release of relay WKP. Relay WKRP on picking up, opening back contact II and closing front contact 89, disconnects the battery I3 from the line wire WI and completes the connection for relay WR. to the line wire CL around battery I3. With relay LPS picked up, closing front contact 91, the relay LVP is energized at reverse polarity and its reverse polar contacts 63 and 89 are closed. On the next step in the operation, the relay WKP is released, closing back contact 81 to complete the connection from terminal NI of battery I2 to the line wire WI Consequently, switch control current now flows from terminal C of battery it over line wire CL to the field station, front contact 88 of relay WKRP, winding of relay WR, contacts 65 to Ill, inclusive, back to the office station over line wire WI, front contact 86 of relay LPS, back contact 81 of relay WKP and to the negative terminal NI of battery I2 through the winding of relay WRP and reverse polar contact 89 of relay LVP. Relays WR and WRP are now both energized, the relay WR being energized at reverse polarity and relay WRP being picked up to close its front contact. With relay WR operated to its reverse position, the switch macln'nes SMI and SMZ are operated to move the track switches to their respective reverse positions.

When the polarized relay WR is operated to its reverse position, opening normal polar contact 38, the relay KR is deenergized and released, closing back contact 4! so that the relay WKRP is retained energized after relay WR is operated. At the ofiice station the picking up of relay WRP, opening back contact 95, opens the stick circuit for relay LPS, and relay LPS is released at the end of its slow release period. The connection for relay WRP to the line wire WI is still retained in effect subsequent to the release of relay LPS by virtue of the branch path including front contact II I.

When the movement of the crossover to its reverse position is completed, the relay KR is reenergized at reverse polarity and relay KR on picking up, opening back contact 4|, deenergizes relay WKRP, which relay is released at the end of its slow release period. During the interval between the opening of front contact 83 and the closing of back contact ll of relay WKRP, the line circuit is open and both relays WR. and WRP are deenergized. Relay WRAP, being quick to release, is released to disconnect the battery I2 from the line wire WI and to complete at its back contact 84 the connection from line wire WI through the winding of relay WKP and around the battery I2. The polarized relay WR, however, remains picked up by virtue of its slow release characteristics. When the back contact 'II of relay WKRP is closed, the connection from terminal BI of battery I3 to the line wire WI is completed and indication current is supplied to the associated line circuit. Since this indication current flows through the winding of relay WR in the same direction as the control current which energized the relay to operate it to its reverse position, the relay WR is retained at its reverse position. At the office station the relay WKP is reenergized and picked up. The lamp BL is now illuminated by virtue of its circuit completed at contact member 44, reverse polar contact 63 of relay LVP, front contact SI of relay W'KP and back contacts and 59.

To move the crossover from its reverse position back to its normal position, the switch lever IL is moved from its position R back to its position N. The operating steps following such a movement of the switch lever IL are similar to those described in detail for moving the crossover to its reverse position and the description need not be repeated. It should be pointed out, however, that there is an open interval on the line circuit including line wire WI following the picking up of relay LPS and prior to the release of relay WKP, because of the difierence in the slow release periods of relays WR and WKP. During this interval the relay WKRP at the field station is operated to disconnect the battery I3 from the line circuit and to complete the connection around that battery. Then when relay WKP is released, a connection is completed at the ofiice station for supplying control current from battery I2 to the line circuit according to the position of the lever IL as reflected by the polar relay LVP. This control current operates the polarized relay WR to effect a corresponding movement of the crossover. Again when the movement of the crossover is completed, there is an open interval on the line circuit during the transfer from front contact 80 to back contact 1| of relay WKRAP. During this interval the battery I2 at the ofiice station is disconnected and a connection is completed for the line circuit around that battery. Subsequent to this last mentioned interval, indication current is supplied from battery I3 to the line circuit according to the position of the crossover, and this indication circuit affects. the ofiice station apparatus to establish an indication to indicate the position of the crossover.

In the case of the signal lever 2L and its associated line circuit, control current is supplied to the circuit in response to a movement of the lever for operating the polarized relay 2HR for effecting a corresponding operation of the associated signal. When the corresponding signal is operated, there is an open interval on the line circuit, during which interval the office station battery is disconnected from the line circuit and a connection is completed for the circuit around the battery. Subsequent to such open interval on the line circuit, indication current is supplied to the circuit from the field station battery to effect an indication at the ofilce station for indicating the proceed position of the signal.

It should be pointed out that when the signal RZA, for example, is operated in the manner explained hereinbeiore the corresponding approach locking contacts 65 to 68, respectively, are opened and open the line circuit for the polarized switch controlling relay WR. The relay WR is, however, retained energized over the local circuit including the corresponding back contacts 14 to H. The relay WKP at the office station is deenergized and, on releasing to open front contact EI and closing back contact 64, causes the normal switch indication lamp NL to be extinguished and the OS lamp to be illuminated. Illumination of lamp OS is an indication to the operator that the crossover cannot be operated by the lever IL.

To describe the lockout feature of the present system, let it be assumed that the switch lever IL is moved to its R position while the lamp OS is illuminated and the lockout is in effect. Because relay WKP is released, opening front contact 90, the relay LPS is not picked up in response to the movement of the lever IL, and hence the sequence of operating steps that follow the picking up of relay LPS is not carried out. Let it be now assumed that traflic conditions which have opened the approach locking circuit change so that the line circuit for the relays WR and WKP is restored, the switch lever IL still remaining at its reverse position. The crossover is not operated to a reverse position corresponding to the reverse position of the lever IL since the relay LPS is not picked up because its pick-up circuit is held open at contact member 41. The lamps associated with the lever IL are now all dark, and to regain control the operator must first restore the lever IL to its normal N position so as to be in agreement with the crossover.

The unit principle provided by apparatus embodying my invention permits, as pointed out in the foregoing description, several different devices (switches and signals) to be each controlled and indicated over individual line circuits, and an unbalanced number of such devices when interrelated can be controlled and indicated with a minimum number of line wires extending between the control point and the location of the devices.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In a remote control system, a field station and an office station, a controlled device at the field station operable to a normal and a reverse position, a control lever at the oflice station operable to a normal and a reverse position, indication means at the office station operable to a normal and a reverse position, a polarized relay at the field station for selectively governing the positions of said device, an oflice station relay having a slow release period, two current sources one at each station, a two-wire line circuit extending between the two stations and normally having a winding of the polarized relay and a winding of the office station relay interposed therein means governed by said device to connect the field station source to said circuit to supply current of normal or reverse polarity according to the position of the device to energize said relays, means controlled jointly by said office station relay and said lever to selectively operate the indication means to indicate the position of said device, switching means operative in response to a movement of the lever between its two positions to open the line circuit for a period and to connect the office station source to the line circuit to supply current of normal or reverse polarity according to the position of the lever to correspondingly energize the polarized relay, and means at the field station responsive to such open period of the line circuit to complete a connection of the line circuit around the field station source.

2. In a remote control system, a field station and an office station, a controlled device operable to a given position, controlling means effective when energized to operate said device, a control lever at the oifice station operable to a given position, a two-wire line circuit extending be tween said stations and having a winding of said controlling means interposed therein, a source of current at each station, switching means at the ofiice station controlled by the lever and operative in response to movement of the lever to its given position to open the line circuit for a period and to then connect the oflice station source to said circuit to energize said controlling means for operating the device, means at the field station controlled by the line circuit and responsive to such open period to complete a connection for the line circuit around the field station source, other switching means at the field station controlled by said device and operative in response to movement of the device to its given position to open the line circuit for a period and to then connect the field station source to the circuit, means at the ofiice station controlled by the line circuit and operative in response to the last mentioned open period to complete a connection for the line circuit around the office station source, and a relay interposed in said last mentioned connection efiectively energized by current supplied to the circuit at the field station for indicating the position of said device.

3. In a remote control system, a field station and an office station, a controlled device at the field station operable to a normal and a reverse position, controlling means responsive to the polarity of current supplied thereto for reversibly operating said device, a control lever at the office station operable to a normal and a reverse position, a two-wire line circuit extending between said stations and having a winding of said controlling means interposed therein, two current sources one at each station, switching means at the office station controlled by the lever and operative in response to a movement of the lever between its two positions to open the line circuit for a period and to then connect the oifice station source to said circuit to supply according to the position of the lever current of normal or reverse polarity to the winding of said controlling means for effecting the corresponding operation of said device, means at the field station responsive to such open period of the line circuit to complete a connection of the line circuit around the field station source during the subsequent operation of the device, other switching means at the field station controlled by the device and operative in response to a movement of the device to open the line circuit for a period and to then connect the field station source to the line circuit to supply thereto according to the position of the device current of normal or reverse polarity, means at the ofiice station responsive to such last mentioned open period of the line circuit to complete a connection of the line circuit around the oifice station source, and a relay interposed in said last mentioned connection effectively energized by the current supplied to the circuit at the field station for indicating the position of the device.

4. In a remote control system, a field station and an ofiice station, a controlled device at the field station operable to a first and a second posi tion, a polarized relay for reversibly operating said device, a controller at the ofiice station operable to a first and a second position, a two-wire line circuit extending between said stations and having a winding of said relay interposed therein, a current source at each station, switching means at the oifice station controlled by the controller and responsive to a movement between its two positions to open the line circuit for a period and to then connect the office station source to the circuit to supply to the circuit according to the position of the controller current of normal or reverse polarity to energize the relay for effecting a corresponding operation of the device, means at the field station controlled by the line circuit and responsive to such open period to complete a connection for the line circuit around the field station source, other switching means at the field station controlled by said device and operative in response to a movement of the device to open the line circuit for a period and to then connect the field station source to the circuit supply to the circuit according to the position of the device current of normal or reverse polarity, means at the office station controlled by the line circuit and responsive to the last mentioned open period to complete a connection for the line circuit around the ofiice station source, another relay having a winding interposed in said last mentioned connection and energized by current supplied to the circuit at the field station, and indication means controlled jointly by said other relay and said controller.

5. In a remote control system for railroads, a track switch, a remote switch control lever having a position for each position of the switch, a polarized relay operative to govern the movement of the track switch to its normal and reverse positions, a two-wire line circuit extending between the track switch and the lever and having a winding of said relay interposed therein, two sources of current one adjacent the track switch and one adjacent the lever, circuit means controlled by the lever and operative in response to a movement of the lever between its two positions to open the line circuit for a period and to then connect the source at the lever to the line circuit to supply according to the position of the lever current of normal or reverse polarity to energize the polarized relay to effect a corresponding movement of the track switch, means controlled by the line circuit and responsive to such open period to complete a connection for the line circuit around the source at the switch, other circuit means controlled by the track switch and operative in response to a movement of the switch to open the line circuit for a period and to then connect the source at the switch to the line circuit to supply according to the position of the switch current of normal or reverse polarity, other means controlled by the line circuit and responsive to the last mentioned open period to complete a connection for the line circuit around the source at the lever, another relay having a winding interposed in said last mentioned connection and energized by current supplied by the source at the switch, and a normal and a reverse switch indicator selectively controlled by said other relay and the control lever.

6. In a remote control system, a field station and an ofiice station, a controlled device at the field station having a normal and a reverse position, a polarized relay for selectively governing said device according to the polarity of current supplied to its winding, a control lever at the oifice station having a normal and a reverse position, a slow release relay and another relay at the office station, a two-wire line circuit extending between said stations and having the winding of said polarized relay interposed therein, two sources of current one at each of said stations for supplying current to said line circuit, means including a back contact of said other relay to complete a connection for the line circuit around the office station source and having a winding of the slow release relay interposed therein, circuit means at the field station controlled by said device to connect the field station source to the line circuit for normally energizing said polarized and said slow release relays, switching means controlled by said lever and operative in response to a movement of the lever to open the line circuit for the release period of the slow release relay and to then connect the oifice station source to the line circuit over a connection having a winding of said other relay interposed therein, said office station source connected to supply current of normal or reverse polarity according to the position of the lever to correspondingly energize the polarized relay for operating said device, means controlled by the line circuit responsive to such open period. of the line circuit to complete a connection for the line circuit around the field station source, means controlled by said device and operative in response to a movement of the device to open the line circuit for an interval to deenergize said other relay and restore the connection including said slow release relay, and indication means governed by said slow release relay and said lever for indicating the position of said device.

'7. In a remote control system for railroads, a stretch of track including a track switch, two signals one at each end of the stretch to govern traffic over the stretch, a switch control lever and a signal control lever at a remote ofiice station, a first polarized relay for selectively governing the position of the track switch, a second polarized relay for selectively governing said signals, a first line circuit extending between said station and said stretch including a first control line wire and a common line wire and having a winding of said first polarized relay interposed therein, a second line circuit extending between the station and the stretch including a second control line wire and the common line wire and having a winding of said second polarized relay interposed therein, a switch indication means and a signal indication means at the station, two sources of current one at the station and one adjacent said stretch, means controlled by the switch lever when operated to complete a connection for the first line circuit around the source at the stretch and to connect the source at the station to such circuit to supply current of normal or reverse polarity according to the position of the switch lever for energizing said first relay, means controlled by the switch when operated to complete a connection for said first line circuit around the station source and to connect the source at the stretch to such circuit to control said switch indication means, means controlled by the signal lever when operated to connect the source at the station to said second line circuit to supply current of normal or reverse polarity according to the position of the signal lever to energize said second relay, and means controlled by either signal when operated to complete a connection for the second line circuit around the station source and to connect the source at the stretch to such circuit to operate said signal indication means.

8. In a remote control system for railroads, a stretch of track including a track switch, two signals one at each end of the stretch for governing traific over the stretch, a switch control lever and a signal control lever at a remote office station, a first polarized relay for selectively governing the operation of the track switch, a second polarized relay for selectively governing said signals, a first line circuit including a first control line wire and a common line Wire extending between the station and the stretch and having a winding of said first relay interposed therein, a second line circuit including a second control line wire and said common line wire extending between the station and the stretch and having a winding of said second relay interposed therein, a switch indication means and a signal indication means at the office station, apparatus partly at the station and partly at the stretch operative by virtue of said first line circuit to energize said first relay for operating the track switch in response to a movement of the switch lever and to then operate the switch indication means in response to such operation of the switch, and other apparatus partly at the station and partly at the stretch operative by virtue of said second line circuit to energize said second relay for operating said signals in response to a movement of the signal lever and to then operate said signal indication means in response to such operation of the signals.

9. In a remote control system for railroads, a stretch of track including a track switch, two signals one at each end of the stretch for governing trafilc over the stretch, a switch control lever and a signal control lever at a remote office station, a switch indication means and a signal indication means at said station, a first line circuit including a first control line wire and a common line wire extending between said station and. said stretch, a second line circuit including a second control line wire and said common line Wire extending between said station and said stretch, two sources of current one at the station and one at the stretch, apparatus partly at the station and partly at the stretch operative to selectively govern the position of said track switch by current supplied from the station source to said first line circuit in response to a movement of the switch lever and to then selectively govern the position of said switch indication means by current supplied from the source at the stretch to said first line circuit in response to the effected position of the track switch, and other apparatus partly at the station and partly at the stretch operative to selectively govern the position of said signals by current supplied from the station source to said second line circuit in response to a movement of the signal lever and to then selectively govern the position of said signal indication means by current supplied from the source at the stretch to said second line circuit in response to effected position of said signals.

10. In a remote control system for railroads, a track switch, a field station adjacent the switch, a remote ofiice station, a polarized relay at the field station operative when energized to effect an operation of the track switch according to the polarity of the current supplied to the winding of the relay, a switch control lever at the office station having a normal and a reverse position, a two-wire line circuit extending between the two stations and having said relay winding interposed therein, switch indication means at the ofiice station, two sources of current one at each station, apparatus partly at each station operative in response to a movement of the switch lever to supply to said circuit from the ofiice station source current of a polarity corresponding to the position of the lever to Qnergize said relay for effecting a corresponding operation of the track switch and to then in response to such operation supply to said circuit from the field station source current of the same polarity as that last supplied by the oflice station source to retain said relay energized and to effect a corresponding operation of said switch indication means.

EARL M. ALLEN. 

